1. Field of the Invention
The present invention relates to voice synthesis and image synthesis technologies.
2. Description of the Related Art
A technology for synthesizing a singing voice by use of a computer device is commonly known in the art. For example, Japanese Patent Application Laid-Open Publication No. 2008465130 (hereinafter, JP 2008-165130) discloses a technique for editing data that represents parameters used in voice synthesis. As other examples, Japanese Patent Application Laid-Open Publication No. 2008-170592 (hereinafter, JP 2008-170592) and YAMAHA Corporation. “VOCALOID2 Owner's Manual” August 2007. pp. 113-115 (hereinafter, Yamaha reference) disclose techniques in which real-time voice synthesis is carried out on lyrics to music played by a user, the lyrics having been input beforehand. In addition, the Yamaha reference discloses a display that shows a User Interface (UI) for adjusting voice synthesis parameters.
One use of voice synthesis devices is to create digital content that accompanies images such as games and Computer Graphics (CG) animations. In such content, a proper balance should be maintained between synthesized voices and accompanying images so as to avoid an undesirable impression of incongruity between the two being imparted to a user. JP 2008-165130, JP 2008-170592, and the Yamaha reference each disclose techniques for editing data that represents parameters used in voice synthesis; however, the devices disclosed in these references perform voice synthesis only. If, when creating the abovementioned content, the techniques disclosed in these related documents were to be applied, changes would be made to the parameters used in voice synthesis only; this is likely to lead to an Undesirable imbalance between duly synthesized voices and accompanying unchanged images.